Transcript

BOB HIRSHON (host):

Plants that keep score. I’m Bob Hirshon and this is Science Update.

Like other carnivorous plants, venus flytraps depend on nutrients from insects they trap inside specially-shaped leaves. Now, researchers report in Current Biology how the plant distinguishes between a nutritious insect and a random leaf or stick that happens to land on it. The secret lies in the flytrap’s math skills, according to University of Würzburg biophysicist Rainer Hedrich. He says anything landing on the plant trips tiny sensors.

RAINER HEDRICH (University of Würzburg, Germany):

Touch the sensor once, nothing happens, but the plant memorizes that it was touched.

HIRSHON:

Once there, insects move around, but inanimate objects don’t.

HEDRICH:

When they touch another trigger hair within 20 seconds, the trap closes within a blink of an eye, and this is the end.

HIRSHON:

As the insect struggles, it keeps tripping the sensors. By the fifth time, the plant begins to digest its meal. I’m Bob Hirshon, for AAAS, the science society.